The primary objective of this project was to determine the impact of appropriate rates of swine manure applications to corn and soybeans based on nitrogen requirements of crops and the potential of nitrate leaching to groundwater. Another purpose of this longterm experimental study was to develop and recommend appropriate manure and nutrient management practices to producers to minimize the water contamination potential and enhance the use of swine manure as an organic fertilizer. A third component of this study was to determine the potential effects of rye as a cover crop to reduce nitrate loss to shallow ground water.